The movesLow Kick and Grass Knot have a base power of 20, with an additional 20 when the target's weight is above 10 (22.0), 25 (55.1), 50 (110.2), 100 (220.5), and 200 kg (440.9 lbs.), successively.

The moves Heat Crash and Heavy Slam have a base power of 120, with a subtractive 20 when the target's weight is, relative to the user's weight, ⅕-¼, ¼-⅓, ⅓-½, and <½, successively.

Pokémon weighing more than 20.0 kg (44.1 lbs.) are not eligible to compete in the Fancy Cup.

Pokémon weighing more than 100.0 kg (220.5 lbs.) are not eligible to compete in the Light Cup.

In Gold, Silver, and Crystal, Pokémon weighing less than 100 kg (220.5 lbs.) have a -20 catch rate when using a Heavy Ball, while Pokémon weighing between 100 kg (220.5 lbs.) and 200 kg (440.9 lbs.) have a normal catch rate when using a Heavy Ball, Pokémon weighing between 200 kg (440.9 lbs.) and 300 kg (661.4 lbs.) have a +20 catch rate when using a Heavy Ball, and Pokémon weighing more than 300 kg (661.4 lbs.) have a +30 catch rate when using a Heavy Ball.

In HeartGold and SoulSilver, Pokémon weighing less than 204.8 kg (451.5 lbs.) have a -20 catch rate when using a Heavy Ball, while Pokémon weighing between 204.8 kg (451.5 lbs.) and 307.2 kg (677.3 lbs.) have a +20 catch rate when using a Heavy Ball, Pokémon weighing between 307.2 kg (677.3 lbs.) and 409.6 kg (903.0 lbs.) have a +30 catch rate when using a Heavy Ball, and Pokémon weighing more than 409.6 kg (903.0 lbs.) have a +40 catch rate when using a Heavy Ball.